This invention relates to radio frequency identification devices, remote communication devices, wireless communication systems, and methods of indicating operation.
Wireless communication systems including electronic identification devices, such as radio frequency identification devices (RFIDs), are known in the art. Such devices are typically used for inventory tracking. As large numbers of objects are moved in inventory, product manufacturing, and merchandising operations, there is a continuous challenge to accurately monitor the location and flow of objects. Additionally, there is a continuing goal to determine the location of objects in an inexpensive and streamlined manner. One way of tracking objects is with an electronic identification system.
One presently available electronic identification system utilizes a magnetic coupling system. Typically, the devices are entirely passive (have no power supply), which results in a small and portable package. However, such identification systems are only capable of operation over a relatively short range, limited by the size of a magnetic field used to supply power to the devices and to communicate with the devices.
Another type of wireless communication system is an active wireless electronic identification system. Attention is directed towards commonly assigned U.S. patent application Ser. No. 08/705,043, filed Aug. 29, 1996, now U.S. Pat. No. 6,130,602, incorporated herein by reference, and which describes such active systems in detail.
These systems include integrated circuit devices which include an active transponder and are intended to be affixed to an object to be monitored. The devices are capable of receiving and processing instructions transmitted by an interrogator. A device receives the instruction, if within range, then processes the instruction and transmits a response, if appropriate. The interrogation signal and the responsive signal are typically radio-frequency (RF) signals produced by an RF transmitter circuit. Because active devices have their own power sources, such do not need to be in close proximity to an interrogator or reader to receive power via magnetic coupling. Therefore, active transponder devices tend to be more suitable for applications requiring tracking of a tagged device that may not be in close proximity to an interrogator. For example, active transponder devices tend to be more suitable for inventory control or tracking.
Radio frequency identification devices may be subjected to undesired signals in the field. For example, various electronic devices such as radar, microwave ovens, etc. can emit spurious radio frequency signals into a communication range of a wireless communication system. The presence of such spurious undesired signals can result in rapid consumption of power of batteries of radio frequency identification devices. This degrades available power of such batteries which could otherwise be used for providing communication operations.
This invention provides radio frequency identification devices, remote communication devices, wireless communication systems, and methods of indicating operation.
One aspect of the present invention provides a wireless communication system. The wireless communication system includes an interrogator and a radio frequency identification device. The interrogator is configured to output a forward link wireless signal. An exemplary forward link wireless signal includes an interrogation signal.
The radio frequency identification device includes communication circuitry configured to receive the forward link wireless signal and a spurious wireless signal. The radio frequency identification device further includes indication circuitry coupled with the communication circuitry and configured to indicate reception of the spurious wireless signal within the communication circuitry.
Exemplary indication circuitry includes circuitry operable to emit human perceptible signals. For example, indication circuitry can include an indicator comprising a light emitting device to emit a visually perceptible signal to indicate the reception of spurious wireless signals. Such indication using the indication circuitry can be subsequently utilized to implement actions to reduce the presence of spurious wireless signals. Other aspects are provided in the present invention.